Turbine assembly, turbine inner wall assembly, and turbine assembly method

ABSTRACT

A turbine assembly includes a rotary component rotatable about an axis of a turbine, a plurality of inner wall segments coupled to the rotary component circumferentially around the rotary component and rotatable with the rotary component, a non-rotary component circumferentially surrounding the rotary component, a plurality of outer wall segments coupled to the non-rotary component and disposed to extend toward the rotary component, and a plurality of nozzles extending from each of the outer wall segments, each nozzle having a tip distal from the outer wall segment such that the tips form a seal with the inner wall segments at an inner flow path of the turbine. An inner wall assembly and a turbine assembly method are also disclosed.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

This invention was made with Government support under contract numberDE-FE0024006 awarded by the Department of Energy. The Government hascertain rights in the invention.

FIELD OF THE INVENTION

The present embodiments are directed to turbine assemblies, turbineinner wall assemblies, and turbine assembly methods. More specifically,the present embodiments are directed to turbine inner wall assemblieswith nozzles forming a seal with inner wall segments.

BACKGROUND OF THE INVENTION

A gas turbine generally includes a main flow path intended to confine amain working fluid therein, namely the hot combustion gases.Additionally, a cooling fluid that is independent of the main workingfluid may be supplied to adjacent turbine rotor structural components.Sealing devices thus may be used to shield the rotor components fromdirect exposure to the main working fluid driving the turbine and toprevent the cooling fluid from escaping with the main working fluid.Typical sealing devices may reduce the efficiency and performance of aturbine due to leakage. For example, leakage in sealing devices, such asinter-stage seals, may require an increase in the amount of parasiticfluid needed for cooling purposes. The use of the parasitic coolingfluid decreases the overall performance and efficiency of a gas turbineengine.

A near-flow-path seal (NFPS) is a sealing device that is conventionallypositioned about a nozzle and in between buckets of a turbine. A NFPS istypically intended to form an outer boundary for the flow of combustiongases, so as to prevent the flow of combustion gases from migratingtherethrough.

Certain ceramic matrix composite (CMC) materials include compositionshaving a ceramic matrix reinforced with coated fibers. The compositionprovides strong, lightweight, and heat-resistant materials with possibleapplications in a variety of different systems.

The manufacture of a CMC part typically includes laying uppre-impregnated composite fibers having a matrix material alreadypresent (prepreg) to form the shape of the part (pre-form), autoclavingand burning out the pre-form, infiltrating the burned-out pre-form withthe melting matrix material, and any machining or further treatments ofthe pre-form. Infiltrating the pre-form may include depositing theceramic matrix out of a gas mixture, pyrolyzing a pre-ceramic polymer,chemically reacting elements, sintering, generally in the temperaturerange of 925 to 1650° C. (1700 to 3000° F.), or electrophoreticallydepositing a ceramic powder.

Examples of CMC materials include, but are not limited to,carbon-fiber-reinforced carbon (C/C), carbon-fiber-reinforced siliconcarbide (C/SiC), silicon-carbide-fiber-reinforced silicon carbide(SiC/SiC), alumina-fiber-reinforced alumina (Al₂O₃/Al₂O₃), orcombinations thereof. The CMC may have increased elongation, fracturetoughness, thermal shock, dynamic load capability, and anisotropicproperties as compared to a monolithic ceramic structure.

BRIEF DESCRIPTION OF THE INVENTION

In an embodiment, a turbine assembly includes a rotary componentrotatable about an axis of a turbine, a plurality of inner wall segmentscoupled to the rotary component circumferentially around the rotarycomponent and rotatable with the rotary component, a non-rotarycomponent circumferentially surrounding the rotary component, aplurality of outer wall segments coupled to the non-rotary component anddisposed to extend toward the rotary component, and a plurality ofnozzles extending from each of the outer wall segments, each nozzlehaving a distal tip, the distal tips forming a seal with the inner wallsegments at an inner flow path of the turbine.

In another embodiment, an inner wall assembly includes a rotarycomponent rotatable about an axis of a turbine and a plurality of innerwall segments coupled to the rotary component circumferentially aroundthe rotary component and rotatable with the rotary component.

In another embodiment, a turbine assembly method includes coupling aplurality of inner wall segments circumferentially to a rotary componentand mounting a plurality of outer wall segments to a non-rotarycomponent and disposed to extend toward the rotary component. Aplurality of nozzles extend from each outer wall segment toward one ofthe plurality of inner wall segments. The nozzles form a seal with theinner wall segments at an inner flow path of the turbine.

Other features and advantages of the present invention will be apparentfrom the following more detailed description, taken in conjunction withthe accompanying drawings, which illustrate, by way of example, theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a turbine assembly in an embodiment ofthe present disclosure.

FIG. 2 is a partial cross sectional perspective view of a turbineassembly in an embodiment of the present disclosure.

FIG. 3 is a partial cross sectional perspective view of the inner wallsegment pinned to the rotary component of the turbine assembly of FIG.1.

FIG. 4 is a partial cross sectional perspective view of an inner wallsegment hooked to a near flow path seal segment of the rotary componentof a turbine assembly in an embodiment of the present disclosure.

FIG. 5 is a partial cross sectional perspective view of an inner wallsegment dovetailed to a near flow path seal segment of the rotarycomponent of a turbine assembly in an embodiment of the presentdisclosure.

Wherever possible, the same reference numbers will be used throughoutthe drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a turbine assembly with composite turbine nozzles andintegrated rotating end wall segments forming a seal with the nozzles.

Embodiments of the present disclosure, for example, in comparison toconcepts failing to include one or more of the features disclosedherein, save cooling flow, increase efficiency, reduce loss due to gapsbetween a cantilevered airfoil, eliminate the need for separate nearflow path seals (NFPSs), reduce the number of gaps at the inner flowpath, reduce the amount of pull load, reduce the cooling flow needed, orcombinations thereof.

FIG. 1 shows a turbine assembly 10 including a rotary component 12, aninner wall segment 16, a set of nozzles 18, and an outer wall segment20. The rotary component 12 is rotatable about a central axis of theturbine. Although only one is shown in FIG. 1, the inner wall segments16 are coupled circumferentially around and surround the rotarycomponent 12 and are rotatable with the rotary component 12. Althoughonly one is shown in FIG. 1, the outer wall segments 20 are mounted to anon-rotary component (not shown) circumferentially surrounding therotary component and disposed to extend toward the rotary component 12.A set of nozzles 18 extend from the outer wall segment 20 toward theinner wall segment 16 and form a seal with the inner wall segment 16 atthe inner flow path of the turbine. The nozzles 18 are attached bynozzle pins 22 to the outer wall segment 20 and extend in a cantileveredfashion therefrom. The rotary component 12 is a single piece that is adedicated rotor wheel 13 that is free from physical attachment to eitherthe upstream or the downstream bucket wheel.

FIG. 2 shows a turbine assembly 10 including a rotary component 12including a rotor wheel 13 and a near flow path seal segment 14, aninner wall segment 16, a set of nozzles 18, and an outer wall segment20. The rotary component 12 is rotatable about a central axis of theturbine. A plurality of the near flow path seal segments 14 are mountedcircumferentially around the rotor wheel 13 and rotate with the rotorwheel 13. In some embodiments, the near flow path seal segments 14 areconnected by a dovetail to the rotor wheel 13. The inner wall segments16 are coupled to the near flow path seal segments 14 and are rotatablewith the rotor wheel 13 and the near flow path seal segments 14. Theouter wall segments 20 are mounted to a non-rotary component (not shown)circumferentially surrounding the rotary component and disposed toextend toward the rotary component 12. A set of nozzles 18 extend fromeach outer wall segment 20 toward the inner wall segment 16 and form aseal with the inner wall segment 16 at the inner flow path of theturbine. The nozzles 18 are attached by nozzle pins 22 to the outer wallsegment 20 and extend in a cantilevered fashion. An end of a near flowpath seal segment 14 is visible in FIG. 2.

Different attachment designs between the inner wall segments 16 definingthe rotating flow path and the rotary component 12 may be used. FIG. 3shows a perspective partial cross sectional view of the coupling of theinner wall segment 16 to the rotary component 12 of the embodiment ofFIG. 1. The rotary component 12 includes a rotary coupler 30. In thisembodiment, the rotary coupler 30 includes a pair of outwardly-extendingmounting flanges. In addition to an upper surface 32 forming a seal withthe tips 34 of the nozzles 18, the inner wall segment 16 includes aninner wall coupler 36 complementary to the rotary coupler 30. In thisembodiment, the inner wall coupler 36 includes a pair of wall flangesextending from the lower surface of the inner wall segment 16 to sitadjacent to the outwardly-extending mounting flanges of the rotarycomponent 12. The inner wall segments 16 are fastened to the rotarycomponent 12 by way of wall pins 38 extending into holes in theoutwardly-extending mounting flanges and holes in the wall flanges tomount the inner wall segments 16 to the rotary component 12.

FIG. 4 shows a coupling of the inner wall segment 16 to the near flowpath seal segment 14 of the rotary component 12. The rotary coupler 30includes a pair of axially-extending mounting flanges. The inner wallcoupler 36 includes a pair of L-shaped flanges extending from the lowersurface of the inner wall segment 16 to engage the axially-extendingmounting flanges of the near flow path seal segment 14 of the rotarycomponent 12 that serve as a hook to connect the near flow path sealsegment 14 to the inner wall segment 16, thereby mounting the inner wallsegment 16 to the near flow path seal segment 14 of the rotary component12.

FIG. 5 shows another alternate coupling of the inner wall segment 16 tothe near flow path seal segment 14 of the rotary component 12. Therotary coupler 30 includes an outwardly-extending tenon of a dovetail.The inner wall coupler 36 includes a mortise between two extensions fromthe lower surface of the inner wall segment 16 to engage theoutwardly-extending tenon of the near flow path seal segment 14 of therotary component 12, thereby mounting the inner wall segment 16 to thenear flow path seal segment 14 of the rotary component 12.Alternatively, the tenon may be formed by the inner wall segment 16 andthe mortise may be formed by the near flow path seal segment 14 of therotary component 12 to achieve the dovetail coupling.

The pinning, hooking, and dovetailing couplings may be used with eithera singular rotary component 12 or with a rotary component 12 includingnear flow path seal segments 14. In embodiments where pinning attachesthe inner wall segments 16 to the rotary component 12, the rotarycouplers 30 may continue around the entire circumference without a gap.In hooking or dovetailing embodiments, however, some sort of gap isneeded to allow the inner wall couplers 36 to engage the rotary coupler30. With either a single rotary component 12 or a rotary component 12including near flow path seal segments 14, the gap may be included inthe rotary coupler 30 at a location around the rotary component 12permitting the inner wall coupler 36 to slidingly engage the rotarycouplers 30, thereby coupling the inner wall segment 16 to the rotarycomponent 12. In the case of a rotary component 12 including near flowpath seal segments 14, however, the inner wall segments 16 mayalternatively be coupled to the near flow path seal segments 14 withouta gap in the rotary couplers 30 if the inner wall segments 16 are firstcoupled to the near flow path seal segments 14 and then the near flowpath seal segments 14 are attached to the rotor wheel 13 and there is agap allowing coupling of the near flow path seal segments 14 to therotor wheel 13.

In some embodiments, the composite turbine nozzle assembly includes anouter wall segment 20 as a one-piece segment of an outer side wall tosupport multiple nozzles 18 as singlet cantilevered composite airfoils.The number of nozzles 18 supported by each one-piece outer wall segment20 may be two, alternatively at least two, alternatively in the range oftwo to six, alternatively four, alternatively at least four,alternatively six, alternatively at least six, or any number, range, orsub-range therebetween. The airfoils are attached only to the outer wallsegments 20, leaving a small gap between the tip 34 and the inner flowpath defined by the upper surface 32 of the inner wall segment 16.

In some embodiments, the inner wall segments 16 have an arc lengthgreater than the nozzle pitch of the nozzles 18. In some embodiments,the arc length of the inner wall segments 16 is similar to the arclength of the outer wall segments 20. The number of nozzles 18 sealingwith each one-piece inner wall segment 16 may be two, alternatively atleast two, alternatively in the range of two to six, alternatively four,alternatively at least four, alternatively six, alternatively at leastsix, or any number, range, or sub-range therebetween.

In some embodiments, the rotary component 12 is the rotating rotor wheel13. In such embodiments, each inner wall segment 16 may be made as aone-piece inner flow path segment and may be attached to the rotor wheel13 directly. In other embodiments, the rotary component 12 includes aplurality of near flow path seal segments 14 attached to the rotor wheel13. In such embodiments, the inner wall segment 16 is indirectlyattached to the rotor wheel 13, the inner wall segment 16 being attachedto a near flow path seal segment 14, which is attached to the rotorwheel 13. In either case, the inner wall segments 16 are coupled to therotary component 12. In some embodiments, the inner wall segment 16 ispinned to the rotary component 12. In other embodiments, the inner wallsegment 16 is hooked to the rotary component 12. In other embodiments,the inner wall segment 16 is dovetailed to the rotary component 12.

Making the outer wall segments 20 and the inner wall segments 16 longerreduces the number of the intersegment seals needed, thereby saving thecooling flow.

A preferred design accommodates nozzles 18 that are high-temperaturecomposite airfoils that tolerate higher temperatures with less coolingflow needed, thereby increasing the efficiency of the turbine.

The rotating inner flow path defined by the inner wall segment 16eliminates the need for separate NFPSs, thereby saving cooling flow andincreasing efficiency. The rotating inner flow path defined by the innerwall segment 16 also reduces the efficiency loss caused by a gap betweenthe cantilevered airfoil and the inner flow path.

In some embodiments, the inner wall segments 16 defining the rotatinginner flow path are made of lightweight high-temperature ceramic matrixcomposite (CMC) materials, thereby reducing the pull load and thecooling flow needed.

In some embodiments, the inner wall segments 16 are effectively pinnedto the rotating rotary component 12 due to the relative light weight ofthe CMC material.

In some embodiments, the nozzles 18 are made of lightweighthigh-temperature ceramic matrix composite (CMC) materials, therebyreducing the cooling flow needed.

In some embodiments, the length of the inner wall segments 16 is greaterthan one nozzle 18 or blade pitch, which reduces the number of segmentgaps to seal.

In some embodiments, the inner wall segments 16 defining the CMC innerflow path are attached to a dedicated rotor wheel 13, which is free fromphysical attachment to either the upstream or the downstream bucketwheel.

In some embodiments, a bayonet-style design includes a one-piece outerwall segment 20 and multiple cantilevered CMC airfoils for a stage-2nozzle 18 of a turbine. An outer wall segment 20 accommodates twocantilevered CMC airfoils as nozzles 18, alternatively at least twocantilevered CMC airfoils, alternatively in the range of two to sixcantilevered CMC airfoils, alternatively four cantilevered CMC airfoils,alternatively at least four cantilevered CMC airfoils, alternatively sixcantilevered CMC airfoils, alternatively at least six cantilevered CMCairfoils, or any number, range, or sub-range therebetween.

In some embodiments, a lightweight, high-temperature CMC material of aninner wall segment 16 defining a rotating inner flow path minimizes thepull load and cooling flow needed. The lightweight material permits apinned attachment of the inner wall segment 16 to the rotary component12, which may be a rotating rotor wheel 13. The length of the inner wallsegments 16 may be greater than one nozzle 18 or blade pitch, whichreduces the number of segment gaps to seal. The inner wall segments 16are preferably attached to a dedicated rotor wheel 13 and not to theupstream or downstream bucket wheels.

While the invention has been described with reference to one or moreembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims. In addition, all numerical values identified in the detaileddescription shall be interpreted as though the precise and approximatevalues are both expressly identified.

What is claimed is:
 1. A turbine assembly comprising: a rotary componentrotatable about an axis of a turbine; a plurality of inner wall segmentscoupled to the rotary component circumferentially around the rotarycomponent and rotatable with the rotary component; a non-rotarycomponent circumferentially surrounding the rotary component; aplurality of outer wall segments coupled to the non-rotary component anddisposed to extend toward the rotary component; and a plurality ofnozzles extending from each of the plurality of outer wall segments,each of the plurality of nozzles having a distal tip, the distal tipsforming a seal with the plurality of inner wall segments at an innerflow path of the turbine.
 2. The turbine assembly of claim 1, whereinthe rotary component comprises a rotor wheel and a plurality of nearflow path seal segments mounted circumferentially around the rotor wheeland rotatable with the rotor wheel, wherein the plurality of inner wallsegments are coupled to the plurality of near flow path seal segments ofthe rotary component.
 3. The turbine assembly of claim 1 furthercomprising a plurality of wall pins, wherein each of the plurality ofwall pins extends into one of a plurality of pin holes on each of theplurality of inner wall segments and on the rotary component to coupleeach of the plurality of inner wall segments to the rotary component. 4.The turbine assembly of claim 1, wherein each of the plurality of innerwall segments is connected by a hook to the rotary component to coupleeach of the plurality of inner wall segments to the rotary component. 5.The turbine assembly of claim 1, wherein each of the plurality of innerwall segments is connected by a dovetail to the rotary component tocouple each of the plurality of inner wall segments to the rotarycomponent.
 6. The turbine assembly of claim 1, wherein the rotarycomponent comprises a dedicated rotor wheel free from physicalattachment to an upstream bucket wheel or a downstream bucket wheel. 7.The turbine assembly of claim 1, wherein the plurality of inner wallsegments and the plurality of nozzles comprise a ceramic matrixcomposite material.
 8. The turbine assembly of claim 1, wherein each ofthe plurality of inner wall segments has a segment arc length greaterthan a nozzle pitch for the plurality of nozzles.
 9. An inner wallassembly comprising: a rotary component rotatable about an axis of aturbine; and a plurality of inner wall segments coupled to the rotarycomponent circumferentially around the rotary component and rotatablewith the rotary component.
 10. The inner wall assembly of claim 9,wherein the rotary component comprises a rotor wheel and a plurality ofnear flow path seal segments mounted circumferentially around the rotorwheel and rotatable with the rotor wheel, wherein the plurality of innerwall segments are coupled to the plurality of near flow path sealsegments of the rotary component.
 11. The inner wall assembly of claim 9further comprising a plurality of wall pins, wherein each of theplurality of wall pins extends into one of a plurality of pin holes oneach of the plurality of inner wall segments and on the rotary componentto couple each of the plurality of inner wall segments to the rotarycomponent.
 12. The inner wall assembly of claim 9, wherein each of theplurality of inner wall segments is connected by a hook to the rotarycomponent to couple each of the plurality of inner wall segments to therotary component.
 13. The inner wall assembly of claim 9, wherein eachof the plurality of inner wall segments is connected by a dovetail tothe rotary component to couple each of the plurality of inner wallsegments to the rotary component.
 14. The inner wall assembly of claim9, wherein the rotary component comprises a dedicated rotor wheel freefrom physical attachment to an upstream bucket wheel or a downstreambucket wheel.
 15. The inner wall assembly of claim 9, wherein theplurality of inner wall segments comprise a ceramic matrix compositematerial.
 16. A turbine assembly method comprising: coupling a pluralityof inner wall segments circumferentially to a rotary component; andmounting a plurality of outer wall segments to a non-rotary componentand disposed to extend toward the rotary component, wherein a pluralityof nozzles extend from each of the plurality of outer wall segmentstoward one of the plurality of inner wall segments; wherein theplurality of nozzles form a seal with the plurality of inner wallsegments at an inner flow path of the turbine.
 17. The method of claim16, wherein coupling the plurality of inner wall segments to the rotarycomponent comprises inserting each of a plurality of wall pins into oneof a plurality of pin holes on each of the plurality of inner wallsegments and on the rotary component.
 18. The method of claim 16,wherein coupling the plurality of inner wall segments to the rotarycomponent comprises connecting the plurality of inner wall segments tothe rotary component by a hook.
 19. The method of claim 16, whereincoupling the plurality of inner wall segments to the rotary componentcomprises connecting the plurality inner wall segments to the rotarycomponent by a dovetail.
 20. The method of claim 16 further comprisingmounting a plurality of near flow path seal segments to a rotor wheelcircumferentially around the rotor wheel to form the rotary component.